Pre-stressed snow coaster



Nov. 14, 1967 R. I. SWANSON BEE-STRESSED SNOW COASTER Filed Sept. 3, 1965 fie. 7

INVENTOR. FJ6F I 5/1444/5'0/1/ BY M ATTORNEYS United States Patent 3,352,567 PRE-STRESSED SNOW COASTER Roger I. Swanson, 624 S. Edward, Mount Prospect, 11]. 60056 Filed Sept. 3, 1965, Ser. No. 484,950 Claims. (Cl. 280-12) ABSTRACT OF THE DISCLOSURE A pre-stressed coaster having a flexible concave-convex shell and an elongated flexible U-shaped runner. The runner is abuttingly .aflixed to the convex side of the shell and the relative flexibilities of the runner and the shell cause a flattening of the shell along one diameter thereof. The connections between the runner and shell permits the runner to slide with respect to the shell when the runner strikes an object, thus preventing tearing of the shell at the runner attachment points.

This invention relates to sporting goods and more particularly to a pre-stressed snow coaster.

Saucer-shaped snow coasters are well known in the sporting goods field. They are usually fabricated from either metal or a fibrous glass reinforced plastic. These saucer-shaped snow coasters suffer from a number of serious disadvantages pertaining toboth manufacture and use.

The metallic saucers are heavy and develop jagged edges when slightly deformed by striking a tree or rock. Also they rapidly become dented and lose their smooth surfaces and ability to slide over the snow. The lighter fibrous glass reinforced plastic saucers are fragile and suffer serious abrasion damage when the coasting surface is not perfectly smooth. The plastic saucers also tend to split or tear whenever any object is struck by them.

Snow coasting saucers currently in use are diflicult for the rider to control. The fibrous glass reinforced plastic saucers in particular tend to deform under the riders weight. This deformation increases and makes irregular the surface area contacting the coasting surface, thus resulting in a relatively circular and irregular pivot base that moves from one position to another as the riders weight is shifted. Such a pivot base allows tracking and direction control only to the extent dictated by the contour of the terrain. This often permits uncontrolled spinning, a contributing factor to many serious accidents resulting from riders descending a slope backwards and unable to see upcoming objects. Aside from this dangerous aspect, it is difficult, if not impossible, to control such saucers so that desired turns and maneuvers may be executed.

When manufacturing current snow coaster models, handles must be provided on opposite sides of the coaster so that the rider will have something to grasp. These handles also serve as a means of storing the coaster when it is not in use.

Objects and specifications It is an object of this invention to provide a pre-stressed snow coaster which retains the advantages of saucershaped snow coasters currently in use, and yet, is not subject to the above outlined disadvantages.

More particularly, it is an object of this invention to provide a pre-stressed snow coaster which is capable of withstanding uneven terrain, bumps, and stresses without fracturing.

It is an object of this invention to provide a light prestressed snow coaster which is relatively unaffected by the abrasive effects of the coasting surface.

It is an object of this invention to provide a pre-stressed snow coaster which has a shock resistant member alfixed 3,352,567 Patented Nov. 14, 1967 to the front thereof to prevent fracturing of the coaster when an object is struck.

It is another object of this invention to provide a prestressed snow coaster which may be easily and positively controlled by the rider.

It is an object of this invention to provide a pre-stressed snow coaster which has a short, parallel pivot base which is pre-stressed in such a manner that the runner contact retains its original position on the sled with respect to the rider, thus allowing a controlled change in direction by a mere shift of the riders weight.

It is an object of this invention to provide a pre-stressed snow coaster which can be slowed when the rider so desires.

It is an object of this invention to provide a pre-stressed snow coaster which will not experience uncontrolled spins during descent of the slope.

It is another object of this invention to provide a snow coaster which does not have to be provided with handles during the manufacturing process.

These and other objects of this invention will be clearly understood with reference to the following specification and figures in which:

FIG. 1 is a perspective view of the pre-stressed snow coaster which is the subject of this invention;

FIG. 2 is a cross-sectional view illustrating one mode of attaching the runner to the shell;

FIG. 3 is a perspective view partially in cross-section illustrating another mode of attaching the runner to the shell;

FIG. 4 is a cross-sectional view illustrating another mode of attaching the runner to the shell;

FIG. 5 is a cross-sectional View illustrating yet another mode of attaching the runner to the shell;

FIG. 6 is a side elevation view of the pre-stressed snow coaster which is the subject of this invention;

FIG. 7 is a front elevation view of the pre-stressed snow coaster which is the subject of this invention; and

FIG. 8 is a cross-sectional View showing means whereby the runner may be locked into the runner attachment device.

Briefly, the objects of this invention are accomplished by aflixing a flexible U-shaped runner to the convex side of a flexible, saucer-shaped shell. The relative flexibilities of the runner and shell are such that the surface of the shell is partially flattened along one diameter thereof. This flattening results in a rolling up of the sides of the shell, thus providing handles for the rider. Referring now to the figures several preferred embodiments of this invention will be discussed in detail.

FIGS. 1, 6 and 7 show a saucer-shaped shell 1. A U-shaped runner 10 has been aflixed to the convex side thereof. Preferably, the shell 1 is fabricated from fibrous glass reinforced plastic and the runner 10 is fabricated from the steel wire. The shell initially is in the form of a spherical segment and the runner is initially flat before the two parts are joined by fasteners 20. By way of example it has been found that a A inch diameter wire will provide the desired degree of contour for a 24 inch saucer. Four of these fasteners have been found suflicient and they are preferably spaced near the outside edges of the shell as shown in FIG. 1. When runner 10 is atfixed to the shell 1 it pre-stresses the shell as shown best in FIGS. 6 and 7. That is to say, that the runner 10 bows upward while the shell 1 tends to flatten out along the axis of the runner. This flattening results in a rolling up the sides 15 of the shell. These rolled up sides serve as handles during use of the coaster. Thus, viewed from the side in FIG. 6,

relaxed configuration. The base of U-shaped runner provides a convenient carrying and storing handle 13. It has been discovered that the snow coaster will be most durable when means are provided for fastening the runner to the shell which allow some degree of axial sliding movement between the shell and the runner. The fastener must have a relatively high friction constant such that sliding will occur only when necessary to absorb shock and other stresses on the fastener.

Referring now to FIG. 2, one such mode of attaching the runner to the shell will be discussed in detail. A cupshaped fastener 30 having a shoulder 31 is protruded through an aperture 32 in the shell 1. The cup-shaped fastener 30 has two aligned runner receiving apertures 33 through which the runner 11 is passed. A high friction constant may be obtained partially by controlling the relative sizes of the runner leg 11 and the runner leg receiving aperture 33. Preferably, however, the major portion of the friction constant should be provided by sizing cup-shaped fastener 30 in such a manner that runner leg 11 is drawn into tightly abutting relationship with the shell 1. This may be accomplished, for example, by forming shoulder 31 after runner leg 11 has been passed through the runner leg receiving aperture and the cupshaped fastener has been passed through the aperture 32 in the shell.

During use, when a force is exerted on the runner 10 such as, for example, by striking an object with the handle 13, the force will be absorbed by a sliding movement between runner leg 11 and fastener 30. In this manner, the shearing stress on the runner fastener is kept at a minimum. Since the cup-shaped fastener 30 is positioned near the outer diameter of the shell 1, it does not experience a great deal of abrasive wear from the coasting surface.

When utilizing a fastener such as shown in FIG. 2, the runner 11 is preferably notched in the manner indicated at 70 in FIG. 8. The notch 70 has a shoulder 71 which prevents the runner from being pulled completely free of fastener 31, thus allowing the pre-stressed coaster to relax. The shoulder 71 is positioned so that it lies on the opposite side of fastener 31 from handle 13. In this manner stress absorbing axial movement is allowed when handle 13 strikes an object, but accidental pull out of the runner is prevented.

FIG. 3 illustrates another mode whereby the runner leg 11 may be slidably aflixed to the shell 1. Two axial slots 40 are provided in the shell 1 at the point where it is desired to attach the runner. A strap 41 is passed around runner leg 11 and through slots 40. The width of the strap is less than the length of the slots 40. The strap is welded to the runner leg 11 as indicated at 43 and then drawn tightly and crimped as indicated at 42 to aflix the runner leg 11 in abutting relationship to the shell 1. Of course, the ends of the straps could be joined by banding at 42 depending upon the particular type of material utilized.

In this embodiment, the high co-efiicient of sliding friction between the runner leg 11 and the shell 1 is a product of the abutting relationship of runner 11 and shell 1. As objects are struck by the lead end of the runner 13, or as :any other types of stresses are placed upon the runner 10, the straps 41 merely slide back and forth in axial slots 40. Again, this sliding action prevents the direct subjection of the fastening means to the high shear stresses resulting from impact.

Referring now to FIG. 4 a third mode of slidably affixing the runner to the shell will be discussed in detail. A fastener 50 having a shoulder 54 and a stem 51 is passed through an aperture 52 in shell 1. Aperture 52 may take the form of an axial slot or, alternatively, may merely be a hole having a diameter considerably less than that of the shoulder 54 but considerably larger than that of stem 51.- The runner leg 11 is firmly abutted against shell 1 and welded 53' to the stem 51, thus providing a high friction, slidable coupling. If aperture 52 takes the form of a 4 slot, axial stresses are absorbed by a sliding of steam 51 in aperture 52. If, on the other hand, aperture 52 takes the form of a generally circular hole, both axial and nonaxial stresses are absorbed by the high friction sliding of shoulder 54 and runner leg 11 against shell 1.

While a sliding coupling between the runner leg and the shell such as illustrated in FIGS. 2, 3, and 4 has many attributes, economic factors may dictate that such a coupling not be utilized. FIG. 5 shows one possible mode for rigidly affixing the runner leg 11 to the shell 1. A cup-shaped fastener 60 having an axial recess 64 is spot welded to the runner leg 11 at 63. The fastener 60 is then passed through a receiving aperture 62 in the shell 1 and its upper portion is bent over to form shoulder 61 and thus secure the runner leg to the shell. Alternatively, of course, the fastener 60 may initially be attached to the shell and the runner leg 11 then spot Welded to recess 64. A similar connection might be achieved by merely riveting runner leg 11 to shell 1.

Thus it may be seen, that this invention has provided a novel and useful concept in the art of snow coaster manufacture. The pre-stressing of the fibrous glass reinforced plastic renders it much less susceptible to damage than previous models. In operation, the rider sits on the shell 1 and grasps sides 15. If he wishes to slow his rate of descent he need merely lean back on the saucer and the trailing ends of runner legs 11 and 12 will operate to slow the coaster. Alternatively, he may stand on the saucer utilizing the exposed portions of the fasteners 20 as foot pads. The exposed portions of the fasteners 20 also may be utilized to retain foot straps or bindings. Because of the short pivot distance of the runners, the slight shifting of the riders weight will be etfective to change the direction of descent. The coaster may be carried to and from the coasting area and stored by means of the handle 13 provided by the base of the U-shaped runner 10.

While several preferred embodiments of this invention have been described together with minor modifications, it will be recognized that other modifications may be made without departing from the scope and spirit of the invention. Such modifications are to be deemed as included within the scope of the following claims unless these claims, by their language, expressly state otherwise.

I claim:

1. A snow coaster comprising:

a generally concave shell of resilient material;

a flexible U-shaped runner; and

means for attaching said U-shaped runner to the outer surface of said shell, the legs of said U-shaped runner forming separated elongated members on which said coaster is adapted to slide, said attaching means permitting relative sliding movement of said members with respect to said shell in a direction corresponding generally to the elongated reach of said members.

2. The combination as set forth in claim 1 which further comprises means for preventing the U-shaped runner from being pulled free from said attaching means.

3. A pre-stressed snow coaster comprising:

a flexible,generally circular, concave-convex shell normally having the shape of a shallow segment of a sphere;

an elongated flexible U-shaped runner, being substanmeans for attaching comprises:

a plurality of pairs of relatively narrow slots in said shell, said slots running generally parallel to the legs of said U-shaped runner,

a plurality of straps having a Width which is less than means for securing the ends of said straps such that the U-shaped runner firmly abuts said shell.

5. The combination as set forth in claim 3 in which said means for attaching comprises:

the elongated reach of said members.

8. The combination as set forth in claim 7 in which said means for attaching comprises:

a plurality of pairs of relatively narrow slots in said shell, said slots running generally parallel to the legs of said U-shaped runner;

a plurality of straps having a width which is less than the length of said slots, each of said straps passing through one slot of a given pair of slots, around one leg of said U-shaped runner, and back through the other slot of said given pair of slots; and,

means for securing the ends of said straps such that the a plurality of apertures in said shell, each of said aper- 1O U-shaped runner firmly abuts said shell.

tures having a first width, and being centered along 9. The combination as set forth in claim 7 in which one leg of said U-shaped runner; said means for attaching comprises:

a plurality of fasteners, each of said fasteners having a plurality of apertures in said shell, each of said apera shoulder portion abutting the inside surface of said tures having a first width and being centered along shell, said shoulder portion being larger than said one legof said U-shaped runner; first width; said fasteners also having a stem portion a plurality of fasteners, each of said fasteners having which is smaller than said first width, said stern pora shoulder portion abutting the inside surface of tion being atfixed to said shoulder in such a manner said shell, said shoulder portion being larger than that it passes through said aperture; and, said first width; said fasteners also having a stem pormeans for afiixing said stem portion to said U-shaped tion which is smaller than said first width, said stem runner leg. portion being afiixed to said shoulder in such a man- 6. The combination as set forth in claim 3 in which ner that it passes through said aperture; and,

said means for attaching comprises: means for aflixing said stem portion to said U-shaped a plurality of apertures in said shell, each of said aperrunner leg.

tures being centered along a leg of said U-shaped 10. The combination as set forth in claim 7 in which runner; said means for attaching comprises:

a cup-shaped fastener, said cup-shaped fastener having a plurality of apertures in said shell, each of said a shoulder abutting the inner surface of said shell apertures being centered along a leg of said U-shaped and a cup portion extending through said aperture, runner; said cup portion having means for slidably receiving a cup-shaped fastener, said cup-shaped fastener having the legs of said U-shaped runner. a shoulder abutting the inner surface of said shell A snow coaster comprising: and a cup portion extending through said aperture, shell of resilient material, said shell having the gensaid cup portion having means for slidably receiving eral shape of a portion of the surface of an ellipsoid the legs of said U-shaped runner. which is defined by the partial intersection of said ellipsoid with a generally curved surface; Refe nc s C ed a flexible U-shaped runner; and UNITED STATES PATENTS means for attaching said U-shaped runner to said shell,

the legs of said U-shaped runner forming separated 2219905 10/1940 Pnckman 280 12 elongated members on which said coaster is adapted 3034799 5/1962 Conover 280 18 to slide, said attaching means permitting relative 3'145029 8/1964 Onanketo 280 12 sliding movement of said members with respect to 3190670 6/1965 Reed 280 18 said shell in a direction corresponding generally to 3325567 12/1965 Gavkk 280*12 X BENJAMIN HERSH, Primary Examiner.

L. D. MORRIS, Assistant Examiner. 

1. A SNOW COASTER COMPRISING: A GENERALLY CONCAVE SHELL OF RESILIENT MATERIAL; A FLEXIBLE U-SHAPED RUNNER; AND MEANS FOR ATTACHING SAID U-SHAPED RUNNER TO THE OUTER SURFACE OF SAID SHELL, THE LEGS TO SAID U-SHAPED RUNNER FORMING SEPARATED ELONGATED MEMBERS ON WHICH SAID COASTER IS ADAPTED TO SLIDE, SAID ATTACHING MEANS PERMITTING RELATVE SLIDING MOVEMENT OF SAID MEMBERS WITH RESPECT TO SAID SHELL IN A DIRECTION CORRESPONDING GENERALLY TO THE ELONGATED REACH OF SAID MEMBERS. 